Sandpiper
Active Member
At risk of creating a firestorm, I wanted to post some of my recent findings about interconnecting 120VAC smokes with residential alarm systems. This has been discussed many times before in this forum, and the discussions always digress into a hissing match with no-one proving their point because the arguments have based upon assumptions, opinions, and hearsay instead of upon content from verifiable and reliable sources.
In the interest of getting to the bottom of this controversy in a scientific, polite, and constructive manner, I’d like to ask that you please join in on the discussion, but if do so, that you please use verifiable content and report the content source.
I will start with this:
From the National Fire Alarm and Signaling Code (NFPA72-2010) Handbook:
However, the manufacturers of multiple-station alarms such as GE (now UTC) and Kidde discourage such interconnections. GE offers no explanation. From the GE ESL 320A/350 Series Smoke Alarms
Installation Instructions:
I had assumed that their reasoning was because the UL evaluation of the unit did not include this interconnection. However, now I am not as sure about this assumption and this is why:
Kidde sells a relay which ties into the tandem circuit for the purpose of connection to additional notification appliances. They, also discourage the tie-in of an alarm panel. However, they offer an explanation, but I am not sure how valid their reasoning is. From the Kidde SM120X Relay/Power Supply Module Installation Instructions:
This statement does not make sense to me. I thought all interconnected multiple-station smoke alarms had a means to identify the culprit detector.
Again from the GE 350 Installation manual:
And from the Kidde Model PI2010 Smoke Alarm User’s Guide:
Now I have two questions for the group:
1. Does anyone have experience with the GE or Kidde multiple-station alarms? Can you identify the culprit alarm when one gets set off?
2. Why are the smoke alarm manufacturers discouraging interconnection to the alarm panel, while NFPA 72 encourages it? No unsubstantiated opinions please, we have already heard those… just the verifiable facts….
In the interest of getting to the bottom of this controversy in a scientific, polite, and constructive manner, I’d like to ask that you please join in on the discussion, but if do so, that you please use verifiable content and report the content source.
I will start with this:
From the National Fire Alarm and Signaling Code (NFPA72-2010) Handbook:
29.7.6.7* Installations that include the connection of single- or multiple-station alarms with other input or output devices shall be permitted. An open, ground fault or short circuit of the wiring connecting input or output devices to the single- or multiple-station alarms shall not prevent operation of each individual alarm.
A.29.7.6.7 Such input and output devices include, but are not limited to, relay modules, notification appliances, phone dialers, security control units, heat detectors, and manual fire alarm boxes.
Paragraph 29.7.6.7 was modified for the 2010 edition to clarify that the intent is to permit the interconnection of smoke alarms with other input or output devices. The examples of input and output devices were moved to Annex A. Furthermore, the revised paragraph requires that a failure of the multiple-station interconnecting means not prevent single-station operation of the multiple-station alarms. This coincides with ANSI/UL 217, which requires a fault to allow alarms to operate as single-station alarms.
However, the manufacturers of multiple-station alarms such as GE (now UTC) and Kidde discourage such interconnections. GE offers no explanation. From the GE ESL 320A/350 Series Smoke Alarms
Installation Instructions:
The 320A/350 Series smoke alarms cannot be used in systems with control panels, pullstations, heat sensors, elevator recall, fire door release, etc.
I had assumed that their reasoning was because the UL evaluation of the unit did not include this interconnection. However, now I am not as sure about this assumption and this is why:
Kidde sells a relay which ties into the tandem circuit for the purpose of connection to additional notification appliances. They, also discourage the tie-in of an alarm panel. However, they offer an explanation, but I am not sure how valid their reasoning is. From the Kidde SM120X Relay/Power Supply Module Installation Instructions:
CAUTION: The model SM120X should not be used to connect groups of alarms to a fire alarm panel or to interconnect groups of fire alarms together. Residential alarms do not latch in the alarm condition and they are self-resetting. If an alarm connected to a module has the test button pushed or the alarm momentarily activates, it will activate the module for as long as the unit is in alarm. If more than one alarm is connected to the module and the module is tied to a control panel there will be no way of knowing which unit caused the alarm.
This statement does not make sense to me. I thought all interconnected multiple-station smoke alarms had a means to identify the culprit detector.
Again from the GE 350 Installation manual:
When units are interconnected and one alarm activates, the LED on units sensing smoke lights steadily, and the LED on the others flashes every 4 seconds. This feature allows you to identify which alarms have detected smoke.
And from the Kidde Model PI2010 Smoke Alarm User’s Guide:
WHEN UNITS ARE INTERCONNECTED, only the red LED of the alarm “which senses the smoke” or “is being tested” (the originating unit) will flash rapidly. All other units in the interconnect system will sound an alarm but their red LED’s will NOT flash rapidly.
Now I have two questions for the group:
1. Does anyone have experience with the GE or Kidde multiple-station alarms? Can you identify the culprit alarm when one gets set off?
2. Why are the smoke alarm manufacturers discouraging interconnection to the alarm panel, while NFPA 72 encourages it? No unsubstantiated opinions please, we have already heard those… just the verifiable facts….